Debate over the Trump administration’s new Nuclear Posture Review (NPR) is now in full and predictable bloom. While many of its conclusions demonstrate continuity with the Obama administration’s modernization plans, controversy has centered on two of the review’s recommendations: to deploy new low-yield weapons on sea-launched ballistic and cruise missiles; and to signal the potential for nuclear retaliation against an adversary’s non-nuclear strikes on certain critical targets. Critics accuse the new policy of lowering the threshold for nuclear use. The policy’s authors and their defenders argue to the contrary that Russia’s tactical nuclear arsenal and strategies have lowered the threshold for nuclear use, and buttressing U.S. deterrence capabilities is the safest response.